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#225391 - 30/06/2004 00:21 Defragmenting and system files...
tfabris
carpal tunnel

Registered: 20/12/1999
Posts: 31597
Loc: Seattle, WA
I have disk drive E:. It is formatted as NTFS on Windows 2000.

It is essentially used for storing three things:

- All games are installed to this drive.
- All MP3s are kept on this drive.
- I keep downloads on that drive.

It's a faster disk drive than my other disks, so I put my paging file there, too.

I decided to defragment the drive. I know it won't defragment the paging file, so I temporarily tell Windows to use C for its paging file. Reboot. Defragment, with the intent of putting the paging file back onto E when the defragment was done. That way the paging file will be contiguous after I'm all done.

Now, since I didn't install the OS to that drive, and I'm not running anything that has files locked open on that drive, I would expect that it could defragment the drive 100 percent. Which it does fine. But here's the funny thing.

There's three green stripes on graph. Two near the beginning and one big fat stripe near the middle. The legend says green stripes are "system files". But I took the paging file off of that drive. And there aren't any files on the drive tagged with the "System" flag as far as I know (dir /S /AS and dir /S /ASH reveals nothing).

So what the heck are those system files? NTFS doesn't store its file allocation table at the center of the disk does it? And if the one in the middle is the allocation table, what are the two small green stripes near the beginning of the disk?
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Tony Fabris

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#225392 - 30/06/2004 01:57 Re: Defragmenting and system files... [Re: tfabris]
CommOri
journeyman

Registered: 30/12/2001
Posts: 83
You using a RAID on that box?

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#225393 - 30/06/2004 02:10 Re: Defragmenting and system files... [Re: tfabris]
genixia
Carpal Tunnel

Registered: 08/02/2002
Posts: 3411
Did you manually delete pagefile.sys after moving it to C: ? I wonder if the defragger checks file names.

They could possibly be file allocation tables. Decent filesystems keep more than two hanging around. (That was one of FAT32s vulnerabilities.)
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Mk2a 60GB Blue. Serial 030102962 sig.mp3: File Format not Valid.

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#225394 - 30/06/2004 02:30 Re: Defragmenting and system files... [Re: tfabris]
DeadFire
addict

Registered: 30/05/2002
Posts: 695
NTFS doesn't store its file allocation table at the center of the disk does it?

Perhaps not at the center, but NTFS definitely keeps at least one backup copy of the file allocation table elsewhere in the partition. I learned this recently when I accidentally deleted a partition containing over 20GB of someone else's files. I was able to recover it, though.

On another note, I have a separate partition on my single hard drive, which stores nothing but personal and media files. Win2K's Disk Defragmenter also shows green stripes for me on that partition. No system file of any kind has ever been put there by me, nor were any by Windows AFAIK.

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#225395 - 30/06/2004 03:36 Re: Defragmenting and system files... [Re: genixia]
tfabris
carpal tunnel

Registered: 20/12/1999
Posts: 31597
Loc: Seattle, WA
The way Windows 2000 works, I don't need to manually delete the file as far as I know. I couldn't see a file named Pagefile.sys on that drive after making the change.

It must be something related to the file allocation somehow, I can't think of anything else it could be.

By the way, when I said "center" of the disk, I meant that the stripe is in the middle of the graph. If it were physically at the center of the disk close to the spindle, then it would have been at the left end of the graph. I'm sure you all knew what I meant though.
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Tony Fabris

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#225396 - 30/06/2004 05:13 Re: Defragmenting and system files... [Re: tfabris]
Roger
carpal tunnel

Registered: 18/01/2000
Posts: 5683
Loc: London, UK
Quote:
NTFS doesn't store its file allocation table at the center of the disk does it?


Yes. I think it does. SysInternals' DiskView utility should be able to tell you which file it is.

Fortunately, the NTFS data structures actually have real filenames as well. You even used to be able to do "dir /a $mft" in the root of an NTFS drive to see the Master File Table, for example. It doesn't seem to work in Windows XP, though.
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-- roger

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#225397 - 30/06/2004 13:58 Re: Defragmenting and system files... [Re: tfabris]
image
old hand

Registered: 28/04/2002
Posts: 770
Loc: Los Angeles, CA
more than likely, its the mft. not sure if there is any freeware utilities that will do this task. but, you can install a trial version of Executive Diskeeper and do a bootup defrag to get the MFT and directory structures fixed up, then uninstall.

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#225398 - 30/06/2004 15:50 Re: Defragmenting and system files... [Re: image]
tfabris
carpal tunnel

Registered: 20/12/1999
Posts: 31597
Loc: Seattle, WA
Is there anything wrong with having the MFT in the "middle" of the disk? Is it there for a specific reason, perhaps because that's the best average position so the head doesn't have to travel as far to reach it?
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Tony Fabris

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#225399 - 30/06/2004 16:00 Re: Defragmenting and system files... [Re: tfabris]
Roger
carpal tunnel

Registered: 18/01/2000
Posts: 5683
Loc: London, UK
Quote:
Is it there for a specific reason, perhaps because that's the best average position so the head doesn't have to travel as far to reach it?


Yep. If you assume that the filesystem is going to be hitting the MFT more than any other file, it makes sense to put it in the middle. Then, at worst, the heads only need to move half of their total sweep to get to it.

This can be a big performance win.

Of course, if you're using LBA (or fake geometry), who knows where the blocks have actually been mapped to?
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-- roger

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#225400 - 01/07/2004 14:04 Re: Defragmenting and system files... [Re: Roger]
image
old hand

Registered: 28/04/2002
Posts: 770
Loc: Los Angeles, CA
one of the alternative disk defragmenters (perfectdisk i think) puts the paging file and mft right in the middle for that very same reason. i thought it was pretty nifty.

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